Flight number record

OO 3979

SkyWest Airlines · San Jose to Los Angeles

Route: SJC → LAX
Departs: 07:00
Flights: 270
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s OO 3979, check with SkyWest Airlines. SkyWest Airlines flies under contract for larger airlines, so a ticket for this flight may show a different airline code and number.

OO 3979 earns an A+. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 20 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 3.6 hours. That rests on 270 flights, with a median arrival 17 minutes early.

Set against the rest of the country, OO 3979's record is 20 points better than the US average of 77.6%. That gap is worth roughly 202 fewer late arrivals for every thousand flights.

On time

97.8%

Arrivals under 15 minutes late, of 268 completed flights

Avg delay

214 min

Across delayed arrivals only, not all flights

Cancelled

0.37%

National rate is 1.81%

1 hour+ late

1.5%

National rate is 8.1%

These figures cover 270 flights between July 2025 and June 2026. The median arrival is 17 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

Schedule

When OO 3979 flies

OO 3979 flies SJC to LAX without a single fixed slot. Its most common scheduled departure was 07:00, used on 210 of 270 flights, with 06:45 (48 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 07:00210 flights77.8%
Departs 06:4548 flights17.8%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.

A 07:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and OO 3979 runs 9 points better at 97.8%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

OO 3979 next to SJC to LAX

Every carrier on SJC to LAX combined arrived on time 86.6% of the time across 4,433 flights, so OO 3979 is 11 points ahead of it. SkyWest flew 2,053 flights on the same city pair under all its flight numbers, including this one, and those ran 92.6% on time. Across its whole network SkyWest Airlines managed 79.0%, which this flight beats by 19 points.

OO 3979 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 3979thin sample	270	97.8%	214 min	0.37%	A+
All SkyWest Airlines on SJC–LAX	2,053	92.6%	73 min	0.39%	A+
All carriers on SJC–LAX	4,433	86.6%	54 min	0.77%	A+
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 3979 quarter by quarter

Quarter by quarter OO 3979 held fairly steady: 100.0% in Jul–Sep 2025, 95.4% in Oct–Dec 2025 and 98.5% in Jan–Mar 2026. A spread of 5 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights100.0%
Oct–Dec 202589 flights95.4%
Jan–Mar 202665 flights98.5%
Apr–Jun 202624 flights—

Scale runs 85% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, OO 3979 ranged from 94.9% on Saturday to 100.0% on Wednesday. With about 39 flights behind each day, a spread of 5 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why OO 3979 runs late

One category carries most of the weight here. Carrier accounts for 100% of the 1,281 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Carrier
100%

The largest share of delay minutes, 100%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 1,281 of the 1,281 delay minutes reported here. The split is drawn from 1,281 delay minutes reported on OO 3979.

Cancellations are rare at 0.37%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 1.5% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

The same number turns up on three other city pairs in the data, including GRR to DTW (36), DTW to AZO (21) and AZO to DTW (21), but none flew often enough under OO 3979 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SJC to LAX only.

One caution: this is a thin sample. 270 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking OO 3979

For a booking, OO 3979 has one of the better records a US domestic flight can show: 97.8% on time and 0.37% cancelled. That is a base rate, not a promise about any single day.

Where to go next

A flight number here means SkyWest Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures